Tautology  

Tautology is used in rhetoric and logic, with slightly different meanings in each context.

In rhetoric, tautology refers to the redundant use of words or phrases that effectively repeat the same idea without adding new information. It is often seen as a stylistic error or a sign of poor writing. For example, phrases like “a free gift” or “a true fact” are considered tautologies because the words “free” and “true” are already implied by “gift” and “fact,” respectively.

However, tautologies can also be employed intentionally as a rhetorical device to emphasize a point, create a memorable phrase, or add a poetic quality to the language. In such cases, repeating an idea using different words can make the message more impactful or persuasive.

In logic, a tautology has a more specific meaning. It refers to a statement that is always true, regardless of the truth values assigned to its constituent parts. A logical tautology encompasses all possible scenarios, making it inherently accurate. For instance, the statement “either it will rain tomorrow, or it will not rain tomorrow” is a tautology because it covers all potential outcomes and cannot be false.

Example: Rhetorical tautologies

• The reason is because
• I personally believe
• Past history
• Completely finish
• Unexpected surprise
• Repeat again
• Exactly the same  

Types of tautology

Here are some of the main types of tautologies, each with its own specific characteristics and uses. 

Rhetorical tautology

Rhetorical tautology involves the unnecessary repetition of an idea using different words. It is often considered a stylistic fault or a sign of poor writing because it adds redundancy without providing new information or insight.

The same concept is expressed multiple times using synonyms or closely related words in rhetorical tautologies. This repetition can make the text or speech seem wordy, inefficient, and less effective in conveying the intended message.

Examples: Rhetorical tautologies

• I saw it with my own eyes.
• The end result was a success. 
• The speaker reiterated the same point multiple times.
• The consensus of opinion among the experts was unanimous.

Logical tautology

A logical tautology is a statement that is necessarily true due to its logical structure, as it encompasses all possible truth values of its constituent parts. While tautologies play a crucial role in fields like mathematics, computer science, and philosophy, they are often considered uninformative or redundant in everyday language because they do not provide new insight or meaningful information about the world.

Examples: Logical tautologies

• Either the sun will rise tomorrow, or it will not rise tomorrow.
• The car is red, or the car is not red.
• A square has four sides because a square is defined as a four-sided shape.
• The statement is true, or the statement is false.

While logical tautologies are inherently redundant and uninformative from a strictly logical perspective, they can be employed in everyday language and communication to convey a sense of certainty, emphasis, or inevitability about a given situation, even if the statement itself does not provide any new or meaningful information.

Examples: Non-literal logical tautologies

• A deal is a deal. [i.e., an agreement must be honored, regardless of the circumstances]
• War is war. [i.e., the harsh realities of war are inevitable and must be accepted]
• Business is business. [i.e., in commerce, decisions are made based on financial considerations, not personal feelings]
• The past is the past. [i.e., what has happened cannot be changed, and one must move forward]

Should you avoid using tautologies?

In most cases, it’s best to avoid using tautologies, especially in formal writing, as they are often viewed as stylistic errors that make your writing seem repetitive, wordy, or less sophisticated.

Tautologies frequently arise when you include a synonym or a phrase that expresses the same idea as another word already present in the sentence. To improve the clarity and conciseness of your writing, identify and remove any redundant words or phrases that do not add new meaning or value to your message.

Examples: Fixing tautologous statements

Incorrect Tautologous Statement	Corrected Statement
I’m arriving at 6 a.m. in the morning.	I’m arriving at 6 a.m.I’m arriving at 6 in the morning
Aaron made an unintentional mistake.	Aaron made a mistake.
You can use the ATM machine over there.	You can use the ATM over there.
The event was a complete sellout, and no tickets remained.	The event was a sellout.
She reiterated the same point again.	She reiterated the point.She made the same point again.

While tautologies are generally considered a stylistic fault and should be avoided in formal writing, they can be effectively employed in various contexts, such as creative writing, political discourse, marketing, and casual conversation. In these situations, tautologies emphasize a point, evoke a strong emotional response, or express a sense of inevitability or certainty.

For instance, the phrase “it is what it is.” This expression is technically redundant since it doesn’t provide any new information; however, it is frequently used to express a feeling of resignation or acceptance in the face of a challenging or unchangeable situation.